EBT Motorcar M-3 Restoration

This page details the restoration work performed on the
EBT railcar M-3 during 2005 and 2006. The goal of the work
was to return the unit to safe and reliable service as a
historic relic.

History of the M-3

From late 1923 to 1924 the East Broad Top constructed a
small enclosed motorized unit for use in inspections of the
line. Built primarily from Maxwell automobile parts and
components fabricated in the EBT shops, the car was larger
than the other maintenance cars the line used.

In 1928 the car was significantly rebuilt using the
drive train and other parts from a Nash automobile. At that
time (two years after the M-1 was built) the car was
christened the M-3.

The M-3 served as an inspection vehicle during the rest
of the railroad's operating lifetime. In 1960 when the EBT
reopened as a tourist carrier, the M-3 was also re-operated.
However the car was stored inoperative sometime in the 1960's.
There were several stories about why. One was that it was run
without enough oil and the engine seized. Another is that a
replacement cam shaft was installed without being hardened
enough and was ground down.

In 2005, with the approval of EBT management, the car was
removed from the railroad for the first time in it's
existence
so that it could be restored to operation.

Back in operation - August 2006

Chris Coleman Photo

Engine Work

Once the M-3 was moved to a location where it
could be worked on, the first order of business
was to remove the engine and send it to a
professional rebuilder, Rhinehold Restorations.
At first the rebuilders had no idea what it was.
After a thorough cleaning of the engine and inspection,
the serial numbers showed that it was Nash, 1924
production. As the car seems to have received the
1924 engine in 1928, it would have been a used engine
at the time it was installed. According to stories
the donor car belonged to a railroad executive at the
EBT.

The restoration shop disassembled the engine to
get a better idea of what would be needed to return
it to service. An initial inspection showed that neither
of the rumored reasons the car was not operable were
true. The engine turned fairly easily once the head was
removed. Some valves were stuck to the head from lack
of use which prevented the engine from turning until
the head was removed. The cam shaft lobes were normal.

After the initial disassembly and cleaning, Heb
Kephart, longtime Rockhill Trolley Museum volunteer,
volunteered his extensive knowledge to implement the
actual engine rebuild. The engine was transferred from
Rhinehold Restorations to Herb's own shop where be set
about the task of bringing the old Nash power plant back
to life.

There were a number of issues, though, most involving
the head and valves. At some time in the life of the engine
the head dropped a valve into the #3 cylinder. When the
piston came up it forced the valve into the head. To repair
the head a slanted hole was bored through the head and a
solid copper rod was inserted. This "injury" may have
been the reason the engine was rendered surplus from its
role in an automobile.

The engine compartment prior to restoration - 2003

Unlike more modern engines, this one has no center
bearing halfway down the crankshaft, leaving only two
main bearings, one at each end. The main bearings were
not worn out, but had been worn to a cone shape from
flexing of the crankshaft. The flexing was a result of
the engine being overreved, possibly due to high engine
speed during backup moves (evading a steam train perhaps?)
The backup gear has a high gear reduction. The crankshaft
itself was of unusually heavy construction, with twice the
mass of a Model T crankshaft.

It was found that the points in the distributor were
the wrong ones for the engine, resulting in a spark that
was not timed for the valve movement. This may be the real
reason the car no longer ran after the 1960's.

During the rebuild, all the pistons, springs, vales,
pistons and bearings were replaced. The original main bearings
were insert, but replacements were poured. Mechanical replacement
parts were used where they fit the engine. Toyota pistons,
Cadillac valves and Chevrolet valve springs were close matches
to the original Nash parts. All new spring tops were made
and heat treated.

The original engine in the car was likely about a 1918
Maxwell. The 1918 engine had the carburetor on the right side
of the engine. This is the side of the car that the fuel tank
was mounted on. As these engines relied on gravity rather
than a fuel pump to deliver gasoline to the carburetor, it would
have been logical to have the tank as close to the
carburetor
as possible. The Nash engine, by contrast, has the
carburetor
on the left side, opposite of the tank. The decision was made
during the restoration to relocate the tank to the left side
to reduce the distance the fuel has to travel to the
carburetor.

The fuel tank itself was another quandary. The original was
made of riveted sheet metal. Adequate in its day, it posed
some safety concerns being in the passenger compartment as
well as potential leaks. For safety, the tank was replaced by
a new one of the same dimensions constructed of all welded
seams. Of additional concern was the means of fueling, which
had been done by flipping up one of the passenger seats to
access the top of the tank. Again for safety, it was elected
to change this feature, adding a hidden external filler tube
in the front wall. A modern safety cap, pressure release, and
overflow were added to the tank to protect from any fueling
accidents. The new fill hole was covered with a door to retain
the car's original appearance.

The restored engine compartment - May 2005

Many parts for the engine were virtually impossible to find.
The fan was only a two blade design and powered by single
oversize V-belt. No automotive or machine shops had a similar
belt, but one was located at an agricultural implements supply
shop.

The radiator was recored and remained original, though with
a slightly different core design. The shroud over the radiator
was originally nickel plated. The nickel planting had long ago
flaked off allowing rust to set in on the shroud. The shroud
was cleaned down to bare metal and was coated with copper first
then chromed (this is standard practice in chroming metal parts
as chrome does not adhere well to bare metal.) Although more
silver than the original nickel's slightly gold color, the
chrome finish will last indefinitely, while nickel will tarnish
and eventually flake.

The Nash emblem that had adorned the radiator shroud was
long missing. An exact duplicate was found on eBay and
installed on the shroud. A new radiator cap was machined from
a block of aluminum to replace the missing original.

The coolant tubes mounted on the engine, to which the
coolant hoses attach, were poorly aligned to match the
actual direction the hoses traveled to the radiator. Both
tubes were removed and angles cut and brazed to create the
correct direction and minimize stress on the coolant hoses.

The distributor cap was missing from the car when the
restoration began. 1924 Nash distributor caps are hard to
come by. The only one that could be located had a section
broken out of it. Carefully, the missing section was filled
in with putty and sanded to shape to match the original shape.

With the recreation of the pilot on the car (more about
that later) it was decided to also recreate the crank starter
that resided in the pilot. The crank was built to look like the
original in the builder's photo, and to be functional as well.
The crank engages the flywheel on the front of the engine and is
spring loaded to retract from the flywheel once the engine
starts. Once the car was mostly assembled it was found the crank
could start the engine in as little as a quarter of a turn.

Once running it was found that the engine ran very smoothly
with little vibration. Initial plans to retrofit the car with
more robust motor mounts were discarded when it was found how
little vibration the engine exhibited when running. However,
the original angle iron that supported the engine in the frame
had become cracked at the bends. These cracks were repaired by
welding.

Transmission

The transmission in the car was the original Nash three
speed manual that would have been mated to the engine during
automotive service. Unlike modern manual transmissions, this
one does not have automatic sychronization of the gears (a
system to get the gears spinning the same speed before being
meshed.) This requires the transmission to be "Double Clutched",
or the cluth engaged both before leaving one gear and again
before entering another.

An inspection of the transmission showed less than 10% tooth
wear, which meant no gearing work was needed. New lining was
installed on the clutch plate.

Rear End

Currently the M-3 has a Ford Model A rear end. The unit
previously seems to have had a Nash rear end. This is
evident because when the Ford rear end was installed the
railroad welded the spline from the Nash rear end to the
Ford rear end. The change out may have been motivated by the
fact that the Ford has lower gear reduction than the Nash,
allowing higher speeds. The Nash rear end was presumably
installed in 1928 with the Nash engine, transmission and
drive shaft. It is not known when the current Model A rear
end was installed. Operationally, the M-3 could travel about
24 MPH in third gear and 8 MPH in reverse at 1800 RPM.

Of the two old Buda wheels that were on the rear of the
car, the right rear wheel was far more badly worn. The rear
end of the car still had differential action, needed when
an auto turns a corner so the outer wheel can follow a longer
arc. Differential action also has the undesirable effect of
causing only the right wheel to spin when traction is lost.
This accounts for the much greater wear on the right rear
wheel. In automobiles, this can be remedied with "limited
slip" where a brake-like appliance keeps the wheels from
turning at a vastly different rate. However, differential
action is not needed on railroad vehicles. The curve arcs
are far wider making the differential in wheel travel almost
inconsequential. Also the slight taper on railroad wheels
compensates for what differential there is. Therefore it was
decided to "lock" the differential, causing both wheels to
turn together at all times. This "Live Axle" keeps equal
power applied to each of the two driving wheels. This will
help in both acceleration and braking.

The main problem with the rear end was that the seals
were a custom size rather than using off-the-shelf
components. This made future maintenance problematic at
best. In order to correct this problem, the tubes on either
side of the differential were removed and tubes from a Ford
F-250 rear end were installed in their place, providing a
modern and robust structure that can better handle the load
and track irregularities. Also when seals need to be replaced
in the future, stock items can be used. The axles from the
F-250 rear end were also installed into the differential.
These axles had the added advantage of directly fitting the
replacement Fairmont M-O-W wheels rather than requiring a
weld job as the Nash axles did.

Suspension, Wheels and Brakes

Inspection of the car revealed many suspension problems.
In addition to several broken leaves, the springs had lost
some of their "spring" causing the car to ride low and the
wheel flanges to eat away at the fenders. The front and rear
spring mounts also had enough lateral slop that springs rubbed
on and cut into the frame. This was due to undersize bolts
installed in the spring linkage. The front axle had about one
inch play side to side.

All four spring sets were replaced with new, modern leaf
springs that cosmetically matched the originals. The leaves
and bolts in all the spring rigging were replaced with those
of the correct size.

Of the four wheels the two Fairmont wheels, on the front,
were still in fairly good condition and were reportedly
replaced in the 1960's (stamped June 1960). The other two
which may have been Buda wheels, were badly worn and had been
welded in their treads. They had also been welded in various
questionable ways to the Nash axle hubs rather than bolted.
The Buda style wheels were originally on all four hubs, but
presumably the front two were replaced due to the same type of
deterioration.

Through the generosity of volunteers and donors, two new
Fairmont wheels were purchased at no small cost. The were
used to replace the badly deteriorated Buda wheels. This
gave the car a matched set of four low (or no) wear wheels
with no welded repairs.

The car as built in 1924 had no brakes on the wheels as
is traditional for similar railroad cars. Presumably the
parking brake, which consists of a band brake on the back
end of the transmission, was used exclusively. This must
have proved inadequate, as during the 1928 rebuild six
wheel brakes were added, two on each front wheel and one on
each rear. The wheel brakes were manual, activated by a tall
lever inside the car.

The old brake lining was found to be worn out and would
do little to help stop the car. It appeared to be made from
the same conveyor belt material that was used on the interior
floor. The brake shoes were separating from the brake lining.
New brake shoes and hangars were fabricated from oak and
steel, and new modern brake lining was applied. Numerous new
sleeves were installed throughout the brake linkages.

Electrical

The electrical harness in the car was entirely replaced
with modern wiring with more reliable insulation. The M-3
is unlike modern automobiles in that it has a 6 volt DC
electrical system rather than 12 volt. Where possible
original dashboard components were reused, but most electrical
switches had to be replaced with new ones. Originally a key
switch was used for the ignition switch with a rotating
outside ring that activated the lights. This switch could
not be repaired so was replaced with a hand switch that had
one position for running and one for running with lights.

The headlight is an unusual design, where an adjustment
extended through the front wall that allowed the position of
the lamp to be faired, changing the tightness of the headlight
beam. The headlight was disassembled and restored.

The M-3 had two horns through most of its life. An "Aooga"
horn is mounted above the headlight in the front wall and a
bellow horn was later mounted on the front left fender. The
original Aooga horn was still on the vehicle when restoration
began, though it was not functional. It was removed from the
car and disassembled. Worn parts inside the horn were repaired
or replaced and the horn was returned to service. When tested
it sounded strangely like the "dive" horns on WWII submarines!

The fender horn was missing from the unit for many years
and it's whereabouts unknown. The original appears to be a
Klaxon, possibly from a Model T. A replacement was located
which, though smaller and newer, closely resembles the original
horn. It is also a 6 volt unit matching the M-3 electrical
system. Unlike the original, it has a mechanical linkage
that sounds the horn. In order to trigger the horn a cable
linkage had to be run to the horn, and to avoid the front
wheels, the location of the horn had to be moved from the
left to the right fender.

The rear tail lights appear to have been from a 1918-24
Model T Ford. One of the tail lights was still in place
while the other one was missing. A nearly identical Model
T tail light was located for the unit. It varied in that it
had a side light to illuminate a license plate and it had a
single contact socket rather than a dual contact socket.
These two features were changed to match the existing socket.

As in most earlier cars, the M-3 has a DC generator rather
than an alternator producing AC current which is then
rectified to DC. The alternator is used today because it
has no segmented commutator to maintain, using solid slip
rings instead. However, generator has the ability to adjust
the position of the contact brushes, thus changing the power
output. The alternator has a varying voltage output based
only on it's rotational speed. Thus, the generator on
different cars had different brush settings based on how
many appliances the operator normally used. The generator on
the M-3 was set to provide enough sustained power to operate
the engine and lights at all times for safety.

The original dashboard voltage meter was repaired and
reinstalled.

Body

After being moved to eastern Pennsylvania, total disassembly
of the car began. Roof, seats, walls, doors, axles, spring
rigging, controls, floors and anything else that could
be removed was removed. The unit was stripped down to the frame
which was completely sandblasted, primed and painted.

The steel composing the frame and substructure of the body
was retained as no replacement was needed. Some broken rivets
were replaced by either welding or bolting as appropriate.

During the disassembly most wood trim was damaged too much
to be reused. This was due to the fact that the screws that
held trim on were puttied over and virtually impossible to
locate. Many of the side and roof boards were cracked, broken
or warped. This led to the decision to replace the body wood
with new material. With the replacements the thickness of the
boards was increased from 3/8 to 7/16 for additional strength.
All new wood was oak. The seat boards were similarly replaced
with new oak.

The floor inside the car was covered with a strange variety
of boards, some tongue and groove and others not, some pine and
some oak. The boards extended only as far as the seats and not
to the outside wall. The boards were in poor condition with
numerous holes, cracks, breaks and rot. The flooring was
covered with a layer of conveyor belt (5 layers of canvas with
rubber coating.) This left only the conveyor belt on the floor
areas under the seats. A complete replacement of the floor
wood was unavoidable. The new wood was oak and extended to the
walls of the passenger compartment. They were covered with an
epoxy coating to extend the life of the wood.

Another peculiarity of the car is that many boards were
held in place by 1/4-18 (18 threads per inch) bolts with square
nuts. As 1/4-18 is effectively impossible to find today, the
bolts were replaced by modern 1/4-20 (20 threads per inch) bolts.

The canvas sides of the car were torn in several places and
patched back together. It was decided to replace the canvas.
As the original canvas could be torn by a simple kick or stray
tool, the new canvas was reinforced by a backing of polymer
FRP board. The sides of the car were primed and painted with
four coats of gloss red.

On the roof, the replacement canvas was used alone as was
the case originally. During installation the canvas was stretched
and stapled into place. it was then coated with boiled
linseed
oil to fill in the pores in the canvas. This prevents the paint
from soaking into the canvas and cracking as the canvas flexed.
The roof was painted it original silver color.

The original lettering on the side of the car was used as a
pattern to create stencils that exactly recreated the original
gold lettering.

Another item the car was missing was the engineer's seat. The
only remnant of the seat were four bolt holes on the floor in the
appropriate locations. Unfortunately, no photos of the interior of
the M-3 showing the original seat have been found. The restoration
crew created an engineer's seat that is a "guestimate" of what
the original may have looked like. It uses the adjustable
top of a piano type stool and a steel base bolted in the
original's location.

One element long missing from the car, even in its common
carrier days, was the pilot (cowcatcher) sported on the front
of the car in its earliest photo. The restorers elected to
recreate this unique element based on historic photos. The
new pilot sets a couple inches above the original to avoid
any complications from switches, crossing and other obstructions
that may have brought an end to the original. As noted above
the pilot included a recreation of the original crank starter.
The pilot is removable should the car need to be shown in its
later configuration.

The side glass assemblies in the car are original, both
the wood and glass. They likely date to the 1924 construction
of the car as the glass has the characteristic flowing nature
of glass of that period. The wood components were sanded,
filled, primed and painted with four coats.

Several photos of the car show that it featured a Model-T
style split front windshield. This means the windshield frame
was hinged and the top pane of glass could be rotated down
behind the bottom pane, to allow ventilation. Sometime after
1956 the windshield was replaced with a single solid pane.
The recesses for the side hinges remained. During the restoration,
the split windshield was also returned to the car. Reproduction
Model T hinges were acquired and a new windshield frame built
around them. The reproduction had to be cut, lengthened and
rewelded to fit the M-3. After the frame was built it was
found that both hinges were right hinges, but this caused no
functional problems and only added to the quirkiness the
railcar already had.

The front of the passenger compartment was made of a
fairly light weight sheet steel. The sheet was actually
in two sections. In the process of removal the sheets were
bent and twisted. It was decided to replace them with a
single sheet of steel, much thicker for safety and
durability. Whereas the original steel could be bent by
impact with a passenger or tool, the new one will remain
rigid and straight. A rear view mirror was also added
for safety

The old hood was in bad shape. The rear (firewall) end
of the hood did not rest on anything. However the steel parts
of the hood were original Maxwell materials and so needed to
be salvaged as much as possible. A wood frame was
built on the firewall to match the hood shape and give the rear
of the hood something to sit on. The hood was reconstructed with
new sheet metal, but with the original louvers welded into place.
Patterns for the hood were first constructed in cardboard and
then the cardboard was used as a pattern to construct the metal
hood pieces.

New front fenders were made from stainless steel to give them
additional service life. The firewall, which is made in the
original Maxwell shape was redone using new varnished oak.